This is a .zip file containing the official Fallout Tactics Multiplayer Demo.
You might have to set the "FTMDemo.exe" to "Run as Admin" and Windows XP on the Windows compatibility options (worked for me even without these changes).
Crashed for me whenever I tried to change the resolution to any x16 in the Display Options (but why would you even want to do something like that?). The x32 all worked fine.
While the Demo worked fine, I couldn't test if the multiplayer works (since my internet sucks and I have no one around to try and connect to anyway).